Flaring red dwarf star (artist's impression): This is an artist's concept of a red dwarf star undergoing a   powerful eruption, called a stellar flare. A hypothetical planet is  in  the foreground. Flares are sudden eruptions of heated plasma that occur when  the  field lines of powerful magnetic fields in a star's  atmosphere  "reconnect," snapping like a rubber band and  releasing vast amounts of  energy equivalent to the power of  100 million atomic bombs exploding  simultaneously. Studying the light from 215,000 older red dwarfs collected in   observations by the NASA/ESA Hubble Space Telescope, astronomers  found 100  stellar flares popping off over the course of a week.

Type: Unspecified : PlanetUnspecified : Star : Feature : Chromosphere : Flare
Category: Illustrations
Release date: 10 January 2011, 19:00
Credit: Artwork Credit: NASA, ESA, and G. Bacon (STScI). Science Credit: NASA, ESA, A. Kowalski (University of  Washington, USA), R. Osten and K. Sahu (STScI) and S. Hawley  (University of Washington, USA)

Hubble NICMOS infrared image of M51: This image by NASA's Hubble Space Telescope shows a face-on view of the spiral galaxy M51, dubbed the Whirlpool Galaxy. Taken in infrared, the image reveals the Whirlpool's skeletal dust structure, as seen in near-infrared light. This new image is the sharpest view of the dense dust in M51. The narrow lanes of dust revealed by Hubble reflect the galaxy's name, the Whirlpool Galaxy, as they appear to swirl towards the galaxy's core.

Name: M 51, Messier 51, Whirlpool Galaxy
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Canes Venatici
Distance: 25 million light years
Release date: 13 January 2011, 21:45
Credit: Credit: NASA, ESA, M. Regan and B. Whitmore (STScI) and R. Chandar (University of Toledo, USA)

Hubble ACS visible image of M51: This image by NASA's Hubble Space Telescope shows a face-on view of the spiral galaxy M51, dubbed the Whirlpool Galaxy. Taken in visible light, it highlights the attributes of a typical spiral galaxy, including graceful, curving arms, pink star-forming regions, and brilliant blue strands of star clusters.

Name: Messier 51, Whirlpool Galaxy
Type: Local Universe : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Canes Venatici
Distance: 25 million light years
Release date: 13 January 2011, 21:45
Credit: Credit: NASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA)

Gravitational lensing of distant galaxies: This diagram illustrates how gravitational lensing by foreground  galaxies will  influence the appearance of far more distant background  galaxies. This means  that as many as 20 percent of the most distant  galaxies currently detected will  appear brighter because their light is  being amplified by the effects of  foreground intense gravitational  fields. The plane at far left contains background high-redshift galaxies. The  middle  plane contains foreground galaxies; their gravity amplifies the  brightness of  the background galaxies. The right plane shows how the  field would look from  Earth with the effects of gravitational lensing  added. Distant galaxies that might otherwise be invisible appear due to  lensing effects.

Name: Galaxies
Type: Early Universe : Galaxy : Type : Gravitationally Lensed
Category: Illustrations
Release date: 12 January 2011, 19:00
Credit: Illustration Credit: NASA, ESA and A. Feild (STScI) Science Credit: NASA, ESA,  S. Wyithe (University of Melbourne, Australia), H. Yan  (Ohio State University, USA),  R. Windhorst (Arizona State University, USA),  and S. Mao (Jodrell Bank  Centre for Astrophysics, and National  Astronomical Observatories of  China)

Hubble observes aftermath of suspected asteroid collision: This is a Hubble Space Telescope picture of asteroid (596)  Scheila,   as observed on 27 Dec 2010. The visible-light  image was taken with   Hubble's Wide Field Camera 3 when the  asteroid was approximately 350   million kilometres away. The  asteroid is surrounded by a C-shaped  cloud, or  coma, of  dust particles. A linear tail of dust can also be  seen   streaming behind the asteroid. The asteroid body, which is    approximately 110 kilometres across, appears star-like because it  is   overexposed so that the faint dust can be imaged. A second Hubble observation on 4 Jan 2011, showed that the  dusty   coma had faded by 30 percent. These data are consistent  with the idea   that Hubble is observing the aftermath of a  collision between Scheila   and a much smaller body that blasted  debris from the surface. This   would be the second time a  collision between two asteroids has been   witnessed.

Name: Asteroid (596) Scheila
Type: Solar System : Interplanetary Body : Asteroid
Category: Solar System
Distance: 220 million light years
Release date: 4 May 2011, 10:40
Credit: NASA, ESA, D. Jewitt (UCLA, USA) and M. Mutchler (STScI)

Swift image of asteroid (596) Scheila: Faint dust plumes bookend asteroid (596) Scheila, which is overexposed  in this composite image. Visible and ultraviolet images from Swift's  UVOT (circled) are merged with a Digital Sky Survey image of the same  region. The UVOT images were acquired on 15 Dec 2010, when the  asteroid was about 375 million kilometres from Earth.

Name: Asteroid (596) Scheila
Type: Unspecified
Category: Solar System
Release date: 4 May 2011, 15:15
Credit: NASA/Swift/DSS/D. Bodewits (University of Maryland, College Park, USA)

Ground-based re-discovery image of asteroid (596) Scheila: Steve Larson of the University of Arizona's Catalina Sky Survey (CSS)  took this image on 11 December 2010, through the Catalina 0.68-meter  Schmidt telescope. Later analysis showed the object to be a re-discovery  of asteroid (596) Scheila, which was discovered in 1906. In the  Larson/Gibbs 2010 image, the asteroid now showed signs of a cometary  tail.

Name: Asteroid (596) Scheila
Type: Solar System : Interplanetary Body : Asteroid
Category: Solar System
Release date: 4 May 2011, 15:17
Credit: S. Larson and A. Gibbs (University of Arizona/Catalina Sky Survey)

Hubble ACS SWEEPS field: Hubble ACS SWEEPS field.

Name: SWEEPS
Type: Milky Way : Galaxy : Component : Bulge
Category: Star Clusters
Constellation: Sagittarius
Release date: 27 May 2011, 17:24
Credit: NASA, ESA, W. Clarkson (Indiana University and UCLA) and K. Sahu (STScI)

Blue straggler formation (artist's impression): This is an artist's concept of a close binary pair of stars that are  merging  to form a blue-straggler-class star. Blue stragglers are so  named because  they seem to be lagging behind in their rate of aging  compared with the  population from which they formed. The merger stirs  up hydrogen fuel  and causes the resulting more massive star to undergo  nuclear fusion at  a faster rate, causing it to burn hotter and bluer.  Probing the star-filled,  ancient hub of our Milky Way, the Hubble Space  Telescope has found blue  stragglers for the first time within our  galaxy's bulge.

Name: Blue straggler
Type: Unspecified : Star : Type : Blue Straggler
Category: Stars
Release date: 27 May 2011, 17:27
Credit: Artwork Credit: NASA, ESA and G. Bacon (STScI). Science Credit: NASA, ESA, W. Clark (Indiana University and UCLA) and K. Sahu  (STScI)

Pluto: 28 June 2011: Pluto on 28 June 28 2011 (WFC/UVIS).

Name: Charon, Hydra, Nix, P4, Pluto
Type: Solar System : Planet : SatelliteSolar System : Interplanetary Body : Dwarf planet
Category: Solar System
Release date: 20 July 2011, 16:10
Credit: NASA, ESA, and M. Showalter (SETI Institute)